But then the physicality of the game has changed. An English top flight footballer in 1976 covered on average 8-11km per game, 25% walking and 10% sprinting. In the 90s that was 12-16km with less walking and more sprinting. Those figures are only going one way. In the recent womens world cup they were outperforming the 70's men for distance and sprint %. They are performing at peaks where recovery time is longer.